SetFactory("OpenCASCADE");

Rectangle(1) = {r_i, -0.05*0.5*(r_i+r_o), 0, r_o-r_i, 0.1*0.5*(r_i+r_o)};
Point(5) = {0, 0, 0};

Physical Curve("inner") = {4};
Physical Curve("outer") = {2};
Physical Curve("bottom") = {1};
Physical Curve("top") = {3};
Physical Surface("bulk") = {1};

Transfinite Line {1,3} = n+1;
Transfinite Line {2,4} = n/4+1;
Transfinite Surface {1};

Mesh.RecombineAll = 1;
Mesh.ElementOrder = 2;
